Flexibility Robust Optimal Operation Strategy for Cross-Regional Interconnected Power Under Load-Source Coordination

Abstract

Ultra High Voltage (UHV) transmission technology is the main regional power interconnection method in China. In addition, renewable energy sources (RES) in China are characterized by centralized distribution. In view of the cross-regional flexible scheduling of large-scale grid-connected RES, we build a day-ahead optimization model which considers the generation economy and robustness of transmission for each regional grid. The model considers the spatial clustering effect of RES and loads, uses robust optimization theory to construct uncertainty sets, and introduces uncertain spatial constraint parameters to compensate for the insufficiency of traditional robust optimization. Furthermore, a coevolutionary algorithm filter-based is proposed to solve above the mixed-integer non-convex nonlinear programming model. Taking the modified IEEE-39 nodes as an example, the results show that the system cost can be reduced by 21.9% by selecting the confidence probability of uncertain variables of both load and source under stable operation, while the prediction accuracy has a significant impact on the system cost when the confidence probability is smaller, and a better operation scheme can be obtained by increasing the space constraint parameters. Finally, the feasibility of the proposed model and algorithm are verified on the Hami power grid in Xinjiang, China.